Scenario 06 Illustrative
Securing a Post-Acquisition Integration
An illustrative acquisition where the buyer checks cybersecurity before connecting networks, so it doesn't inherit an attacker along with the business.
Illustrative scenario, not a client engagement. This is a hypothetical example based on common attack patterns. It shows how we'd approach the problem, and doesn't describe a real client, incident or result.
- Sector
- Energy services
- Scenario
- Mergers & acquisitions
- Written for
- Leadership and IT teams
The situation
A Calgary energy services company agrees to buy a smaller competitor. The deal team has reviewed the finances, contracts and equipment, but not cybersecurity. Leadership wants the two networks connected within 30 days so teams can share systems.
Nobody knows whether the target company has ever been breached, how its systems are configured, or whether an attacker is already inside.
What's at stake
The risks
- Connecting networks could hand an existing intruder access to your whole environment. Marriott inherited an intrusion in Starwood's reservation system that began before the acquisition and went undetected for years.
- Unpatched systems, weak access controls and undisclosed incidents become your liabilities after closing.
- Remediation costs you didn't budget for can erode the value of the deal.
- Integration deadlines create pressure to skip security checks.
Our approach
How we'd help
- Due diligence. Before closing, review the target's security controls, past incidents, internet exposure and key vendors, so the findings can inform price and deal terms.
- Compromise assessment. Before connecting anything, hunt for signs of an existing intrusion in the target's environment.
- Controlled integration. Connect through limited, monitored links, move users to your identity standards and bring devices under your monitoring.
- Uplift. Close the remaining gaps through a 90-day plan, then retire legacy systems you no longer need.
Decisions for leadership
- Make cybersecurity part of due diligence, with findings able to affect price, warranties or indemnities.
- Set a clear gate: no network connection until the compromise assessment is complete.
- Budget for security remediation of the acquired business.
- Decide who owns security for the acquired company during the transition.
Technical notes
- Map the target's external attack surface (domains, IP ranges and exposed services) and check for leaked credentials.
- Deploy EDR across the target's environment to hunt, and review Active Directory for unexpected admins, scheduled tasks and Group Policy changes.
- Review the target's cloud tenants for unknown apps, forwarding rules and privileged accounts.
- Avoid domain trusts until the assessment is complete; use a segmented, tightly filtered interconnect instead.
- Plan identity and tenant migration to your baseline, including MFA and least privilege.
The takeaway
When you buy a company, you buy its security history. Find out what you're inheriting before you connect it.
How we can help
Related reading
Next step
Could this happen to you?
Tell us what you're protecting. We'll help you find the gaps before an attacker does, and plan how you'd respond if one gets in.
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